Indicating lamp receptacle



I Nov. 16,' 1943. A. H. POWELL INDI CATING LAMP RECEPTACLE FiledJuly 25,1941 Jef uw@ '5 HMZ Patented Nov. 1s, 1943 UNi'rvEo STATE s PATENTortica` mmca'rmc Lam aacsrracm Alric H. Powell, Ye'adon, Pa., assignorto General Electric Company, a corporation of New York applicati@ .in iyz3, 1941, serial No. 403,635

s claims. (ci. rive-329) .at I. The Athreads I are formed in the outerMy invention relates to an indicating lamp re-V ceptacle and moreparticularly to a pilot larnp receptacle for use on panel boards.

In many cases, panel boards are provided with indicating or pilot lamps,visible vfrom the front of the board, which give an indication as towhether or not circuits concealed behind the' board are energized. Suchpilot lamps are of low.-

voltage and power consumption and are connected to the energizedcircuits iri,series with a resistor. This requires a special receptacleto port the resistor.

It is an object of my invention to provide an improved receptacle formounting an indicating lamp and associated resistor on av panel board.

wall-of an annular recess 5 which is formed adjacent asleeve B extendinginwardly into the interior of the tube. -Extending through spacedopenings 'i inthe end cap 3 are spaced contact members 8 receiving theindicating lamp L 'Each contact member 8 comprises an elongated stripofflexible material, such as' spring bronze,

one endof whichis provided with a projecting y portion l for engagingthe lamp while the other end is bent in the form of a U i which receivesmount the lamp in indicating position and to sups It is another objectof my invention to provide an improved receptacle for panel board jmounting which comprises relatively few parts, is easily assembled andmanufactured at'low cost.I

A further object oi' my invention is the provision of an improvedreceptacle for panel mount` ing in which a single supporting element isutilized to support the associated resistor and indicating lamp on thepanel.

In the accompanying drawing, Fig. 1 isa per-4 a screw il to form aterminal means for the contact blade. Each contact blade (Fig. 5) isalso provided with a laterally extending tongue i2. In

mounting the contact blades in position on the end cap 3, thelamp-engaging ends of the blades are inserted through the openings 1 andthe blades are pushed through the openings until the `tongues i2 snapinto a recess i3 formed centrallyofthe sleeve `B. Once the contactblades are seated in position on the end cap, they cannotk be dislodgedtherefrom due to the fact that the tongues i2 engage a wall I4 of therecess spective view of my indicating lamp receptacle; Fig. 2 is asectional view through the device;

Fig. 3 is a sectional view taken along line y3--2 of Fig. 2; Fig. 4 is asectional view taken along.

the line I-lof Fig. 2; Fig. 5 is a perspective .f view of one of theterminal contacts, and Fig. 6

is a diagrammatic view showing the indicating f lamp connected to anenergized circuit. Y

Referring to Fig. 6 of the drawing,` a, pilot or indicating lamp L and aresistor R are shown in,

diagrammatic form as connected in series across line conductors C, theenergization of which is to be indicated on the panel board. Wheneverthefaces 9 which are normally biased toward each other by the springtension of the contact blades.

conductors C are energized, the lamp L will be lighted. The lamp-L isvisible from the front of.v the panel board `which conceals theconductorsV C and the resistor R and at the same time pro-r tectsit'from possible damage. The lamp and resistor are carried by areceptacle mounted on the panel board.

Referring to Fig. 2 of the drawing, my receptacle includes a support iwhich is in the form of a metal tube threaded throughout the entirevlength of its external surface, as indicated at 2. At one end, the tubei s closed by acap l which may be formed of any suitable insulatingmaterial, such as a molded plastic, and which is threaded on the end ofthe tube, as indicated Il, preventing the contact blades from beingrevmoved lengthwise from the, end cap. Movement of the contactbladesin'the opposite direction is prevented by shoulders i5 whichengage the walls of the cap adjacent the openings 1. Those portions ofthe contact blade which extend beyond the confines of the tube I and cap3 are held ilrmly in assembled position by being seated in grooves i6`formed in an extension i1 of the The ,contact surfaces 9 are held aparta predetermined distance by a separator 28 which is formed oi'insulating material, such as a molded plastic, and which is providedwith arms 2s for insertion through openings 30 formed in the contactblades 8. In assembled position, the contact blades are biased inwardlyagainst the outer edges of the separator 28 so that the contact surfaces9 are spaced apart a distance sufiicient to permit easyinsertion of theguide plug 26 when the indieating lamp is to be mounted in position. As

long as the lamp base is positioned to present the tapered surface 21 tothe contact blades, the lamp may be easily seated in position with theferrules 25 in engagement with the contact blades, in the manner shownby Fig. 2. The width of the plug 26 is such, however, as shown by Fig.3, that if the lamp is turned toa position sothat the ferrules will notengage the contact blades, the plug will engage the ends of the contactblades so that the lamp cannot be inserted in position.;

Thismeans that it is impossible to-mountjthe lamp in positionincorrectly.

The contact blades and lamp L are electricallyl isolated from the metalsupporting tube I by a position. In mounted position, the indicatinglamp is visible from all points in iront of the l panel while the.resistor and wiring to the receptac'le`v are hidden out of sight behindthe panel.

The indicating lamp may be easily replaced simply by removing the cap 39and inserting a new lamp linto contact with the blades l. This may bedone without disturbing the mounting oi' the receptacle on the panel.The lamp cannot be pushed into the tube too far since the base 276 willengage the separator .28. to adjust the liner 3| of insulating material,such as an impregnated fiber, whichv extends the full length of the tubeI. A sleeve 3i `of similar insulating material is located withinA theliner to Vassist in f centering the lamp in podtion.r

The resistance R which cooperates -with the I lamp L is likewisesupported onthe tube I. The

resistance comprises a windingl 32 of any suitable vresistance wire upona shell 33.01' insulating material, such as a ceramic sleeve. One end oftl'ie resistance wire is connected to a terminal '34 formed of a stripof'metal wrapped around the shell and provided with a terminalscrew I5;the other end of the resistance wire is connected by a heavyconducting'lead 30 lto one oi the terminals lamp to correct mountedposition, as indicated by Fig. 2.

My receptacle is one which is rugged in construction since it provides asingle mounting support for both the resistor R and the lamp L on f themetal tube I.

The length of the tube may be varied at will to accommodate thereceptacle i to' a wide variety of panel board thicknesses and resistorlengths. 'I'he same results can be attained within the limits of thetube length by adjusting the lock nuts 31 and 44. T h'e entire #lengthofthe resistor is supported on the tube so that there yis no dangerofbreakage due to -the tube I.

y receptacle is not sublectto breakage by vibration or shock.

lov of a contactbiade l. The-resistance wire, terminal 'strip 34 andleadwire 30 are secured in position onIk the shell 33; by a heavy coating oiinsulating material, such as a vitreous enamel. The resistor isassembled in position ou the mounting tube I by ysliding it over 'theend o! the tube into engagement with :the end cap I against which it isllocked in position by a lock nut 31, the lock nut being insulated fromthe sleeve by a washer ,38 of insulating material, such as sheet ber.Alternatively, the'resistor may bemounted in position prior to assemblyof the end cap and' contacts by placing it over the tube against thelockvnut 31 and then assembling the cap 3 in position. Y

The receptacle is provided with'an end cap 39 which is formed oftranslucent material. such as glass or a suitable plastic, so thatthelamp L is visible from any point at the iront of the panel board. Thecap may be colored to give a designationv of the circuit to which theindicating de vice is connected. The end cap is screw threaded, asindicated at 40. into what might be termed an escutcheon nut A4I whichin turn is screw threaded to the supporting tube I, as shown at 42. Aportion of the colored cap l! extends into the interior of theinsulating sleeve, as shown at 43, so that the metal supporting tube Ivis completely insulated throughout its'length. Prior to closing the endoi' the Supporting tube by the escutcheon nut 4I, a lock nut 44 isthreaded onto the end of the tube and is spaced from the accidentalcontact therewith. ,Moreoven the lamp isi totally enclosed within andprotected by 'Ilieiconstruction is such that the The receptacle isconnected into a circuit simply by running lead wires to the terminal 34and .onel of the terminals I0. Since the lead wire ll of the resistoris'secured tothe otherv terminal i0-, the lamp and resistor will beconnected in series according to the circuit diagram oi! Fig. 6.

What I claim as new and :desire to secure by Letters; Patent of theUnited States is:

,1. In a receptacle for a switchboard lamp, a

, tube,a cap of insulating material closing one end or said tube, spacedcontact members carried by Asaid capnd having contact surfaces extendingintothe interior'oi said tube and being provided with terminal portionslocated outside said tube,

asleeveof insulating material surrounding said tube, a. resistor forconnection to a terminal portion surrounding and supported on saidsleeve, and means for mountingvsaid tube on a support,

said contact surfacesbeing` adapted to supply current toalamp insertedin the `other end of said tube.

2. In a lamp receptacle, a tubular member, a

. cap of insulating material closing one end of said escutcheon nut toreceive a panel board 45. The

.lock nut 44 may be adjusted laterally along the length of the tubebetween the other lock nut 31 l and the escutcheon nut 4I toaccommodate'variou; sizes of mounting panels.

In mounting the deviceon the panel, the lock nut 44 is rst adjustedapproximately in accordlance with the thickness of the panel on whichthe receptacleis to be mounted and'then the escutcheon nut 4I is removedfrom the mounting tube I so that the latter may be Yinserted v throughan opening drilled in the panel board.

Thereafter, the escutcheon nut 4I is replaced on the tube and the locknut 44 tightened up against the back ofthe panel to fasten thereceptacle in tube, spaced contact members carried by said cap i `ingtube, a cap of insulatingl material closing one end of saidtube, spacedcontact members carried by said cap` extending intothe interior of .saidtube and Ibeing provided with contact surfaces for electricallycontacting a lamp to be inserted in the other end of said tube, a linerof insulating material disposed in said tube and insulating said contactmembers from said tube, and a resistor carried by said tube and beingsupported throughout its length thereby.

4. In a lamp receptacle, an externally threaded tubular member, a capthreaded on one end of said member, spaced contact members carried bysaid cap extending into the interior of said member and being providedwith contact surfaces for electrical connection to a lamp to be insertedin the other end of said member, a sleeve of insulating materialsurrounding a portion of said tubular member, a resistor carried by saidsleeve for series connection with one of said contact members, and alock nut threaded on said tubular member and forcing said sleeve againstsaid cap.

5. In a lamp receptacle, an externally threaded tubular member, a capthreaded on one end o! said member, spaced contact members carried bysaid cap and extending into the interior of said member and beingprovided with contact surfaces for electrical connection with a lampinserted in the other end of said member, a sleeve of insulatingmaterial carrying a resistor surrounding a portion of said tubularmember. means threaded on said tubular member and clamping said sleeveagainst said cap, and means for closing the other end of said tubularmember including a cap of translucent material.

6. In a lamp receptacle, an externally threaded tubular member, a capthreaded on one end of said member, spaced contact members carried bysaid cap extending into the interior of said member and being providedwith contact surfaces for electrical connection with a lamp to beinserted in the other end of said member, a sleeve of insulatingmaterial surrounding a portion of said tubular member, a resistorcarried by said sleeve for series connection with one of said contactmembers, a lock nut threaded on said tubular member and clamping saidsleeve against said cap, means for closing the other end of said tubularmember-including a cap of translucent material, and means for mountingsaid tubular member in an opening in a support with the translucent capon one side of said support and the resistor on the other side.

ALRIC H. POWELL.

